Many decades ago, interlaced video processing was developed for the transmission of video sequences, namely a collection of video frames each containing an ordered number of scan lines. Interlaced video processing includes an interlaced scanning operation where a video frame is transformed into even and odd fields. In addition, the even and odd fields are processed and converted back into a video frame for display. Examples of various types of processing operations include compression and decompression for example.
Typically, interlaced video processing is accomplished by separating a video frame 100 into even and odd fields as shown in FIG. 1. The odd field 130 contains odd numbered scan lines 110 of the video frame 100 while the even field 140 contains all even numbered scan lines 120. One disadvantage with the interlacing process is that it requires a transmitter to employ enough buffer memory to store an entire frame of data. For instance, frame buffer memory would be used to store the even field 140 while the odd field 130 is routed to a coder/decoder (codec), such as a Motion Picture Experts Group (MPEG) codec for example. The MPEG codec performs compression operations on the odd field 130 and subsequently the even field 140 as well. Another disadvantage is that the interlacing process produces a greater number of visual artifacts because existing devices perform digital filtering or other operations on the fields 130 and 140, which may cause adverse effects on the clarity of the image.
After MPEG compression and decompression, the fields are combined again into a frame by a process called deinterlacing. In order to perform the deinterlacing process, buffer memory sized to accommodate at least one field of data is required. This buffer memory stores the previous field that has to be present at the same time with the current field. Again, the deinterlacing process introduces visual artifacts because of some further processing performed usually during deinterlacing.
Recently, a newer and superior video processing method called “progressive” video processing has been developed. Progressive video processing permits an entire image to be displayed sequentially from top to bottom without the odd/even interlacing. In other words, instead of the video frame being split into two fields, one containing odd numbered scan lines and the other containing even numbered scan lines, the video frame is completely scanned from top to bottom in one pass. The problem with many products supporting progressive scanning is that expensive, less common codecs are needed rather than less expensive codecs solely supporting interlacing (referred to as “interlaced codecs”). This increases product costs which are passed on to the consumer.
Thus, there would be benefits in developing a system and method that supports progressive video processing but uses interlaced codecs.